Pesticidal phosphoro and phosphono acetylhydrazides

ABSTRACT

This invention is for novel pesticides having the general formula   WHEREIN R is lower alkyl; R&#39;&#39; is lower alkyl or lower alkoxy; the radicals represented by X are independently selected from the group consisting of oxygen and sulfur; R2 and R3 are independently selected from the group consisting of hydrogen, methyl, ethyl, formyl, acetyl, and in combination can be selected from the group consisting of ethylidene and methylene. The lower alkyl radicals suitable for R and R&#39;&#39; are the straight and branched chain aliphatic radicals having from one to eight carbons, and include for example, methyl, ethyl, n-propyl, isopropyl, amyl, octyl, and the like. Similarly the lower alkoxy radicals suitable for R&#39;&#39; are the straight and branched chain radicals having from one to eight carbons and include methoxy, ethoxy, n-propoxy, isopropoxy, amoxy, octoxy and the like. Particularly effective as pesticides in the control of insects such as M. domestica, B. germanica, and O. fasciatus. They are also effective in the control of acarids, such as Tetranychus telarius, both contact and systemic.

United States Patent Fearing [451 July 18,1972

[54] PESTICIDAL PHOSPHORO AND PHOSPHONO ACETYLHYDRAZIDES [60] Division of Ser. No. 629,401, April 10, 1967, Pat. No. 3,518,327, which is a continuation-in-part of Ser. No. 423,356, Jan. 4, i965.

[52] U.S. Cl ..424/2ll [5 1] Int. Cl. .A0ln 9/36 [58] Field ofSearch ....424/2l1 [56] References Cited OTHER PUBLICATIONS Kreutzkamp et al. C. A. Vol. 57, 5946-5947 (1962).

Primary Examiner-Stanley J. Friedman Attorney-Wayne C. Jaeschke and Edwin H. Baker [57] ABSTRACT This invention is for. novel pesticides having the general formula wherein R is lower alkyl; R is lower alkyl or lower alkoxy; the radicals represented by X are independently selected from the group consisting of oxygen and sulfur; R and R are independently selected from the group consisting of hydrogen, methyl, ethyl, formyl, acetyl, and in combination can be selected from the group consisting of ethylidene and methylene. The lower alkyl radicals suitable for R and R are the straight and branched chain aliphatic radicals having from one to eight carbons, and include for example, methyl, ethyl, n-propyl, isopropyl, amyl, octyl, and the like. Similarly the lower alkoxy radicals suitable for R are the straight and branched chain radicals having from one to eight carbons and include methoxy, ethoxy, n-propoxy, isopropoxy, amoxy, octoxy and the like. Particularly effective as pesticides in the control of insects such as M. domestica, B. germanica, and 0. fasciarus. They are also efi'ective in the control of acarids, such as Tetranychus telarius, both contact and systemic.

5 Claims, No Drawings PESTICIDAL PHOSPHORO AND PHOSPHONO ACETYLHYDRAZIDES wherein R is lower alkyl; R is lower alkyl or lower alkoxy; the radicals represented by X are independently selected from the group consisting of oxygen and sulfur; R and R are independently selected from the group consisting of hydrogen, methyl, ethyl, formyl, acetyl, and in combination can-be selected from the group consisting of ethylidene andmethylene. The lower alkyl radicals suitable for R and R are the straight and branched chain aliphatic radicals having from one to eight carbons, and include for example, methyl, ethyl, n-propyl, isopropyl, amyl, octyl, and the like. Similarly the lower alkoxyradicals suitable for- R are the straight and branched chain radicals having from one to eight carbons and include methoxy, ethoxy, n-propoxy, isopropoxy, amo'xy, octoxy and the like.

The general process forpreparing the novel pesticides may be illustrated by the following reaction:

wherein R, R, X, R and R are as hereinabove defined; and I R is a lower alkyl. The reaction is preferably carried out in the presence of a solvent selected from the group consisting of primary, secondary, and tertiary aliphatic alcohols which include for example, methanol, ethanol, propanol, butanol, and the like, but no solvent is required. Alcohols in excess of five carbon are not as desirable as the lower alcohols because the higher boiling points of the former make separation difficult in that the product is more likely to decompose when distilling at the higher temperatures required.

The temperature of the reaction, broadly 0C. to 50C., is not critical, but must not be so high as to cause the formation of side products, or so low as to require an excessively long reaction time. The preferred temperature range is between about 25 and 35C.

Stoichiometric quantities of the reactants are used and the reaction is only mildly exothermic so that it may be easily controlled. After removing the by-product alcohol by distillation, a pure phosphoro or phosphono acetylhydrazide may be recovered by washing the reaction mixture with water or aqueous solutions of sodium carbonate. For convenience, the 7 reaction mixture may first be dissolved in an inert organic solvent such as benzene, ether, and the like, and then washed. Normally the reaction will yield between 60 and 93 percent of the theoretical predicted amount of phosphoro acetylhydrazide or phosphono acetylhydrazide.

The preparation of the dialkyl phosphoro and phosphono thio and dithio acetate intermediates is illustrated by the following reaction:

PS CHzCOR NaCl .H. h wherein R, R, R and X are as previously defined. An example of the preparation of one specific inten'nediate useful in this invention follows.

CzHu s I S CHzC-C 02H:

I To a reaction h5g1? fitted witha thermometer and stirrer An alternative process for preparing the novel pesticides is illustrated by the following reaction.

where M is an alkali metal, such as sodium or potassium, and R, R, X, X, R and R are as hereinabove defined. The condensation reaction (2) can be conveniently carried out in the presence of a solvent, described supra, but no solvent is required.

The preparation of the intermediate N,N-dialkyl chloroacetylhydrazide hydrochloride used in Equation (2) can be illustrated by the following reaction:

X CICIIAHJCI NHgN wherein X, X, R and R are as previously defined.

The following specific examples illustrate thepleparation of the novel compoundsof the invention.

EXAMPLE 1 Hg (at 40C.) to remove the ethanol. cc. of benzene was added and the solution was washed with successive 50 cc. portions of water, 2 percent aqueous sodium carbonate solutions, and water. The product was then concentrated at 1 mm. Hg to 60C. to give 28 grams (0.10 mol) of diethyl phosphorodithioacetyl hydrazide having an index of refraction N J .5370; an average analysis of 8.97% N as compared to 10.8% N, theoretical.

EXAMPLE 2 II II 1SCH NHNlI icaHro To a reactor flask fitted with a thermometer and stirrer was added 42 grams (0.14 mol) of ethyl diisopropyl phosphorodithioacetate dissolved in 60 ml. of ethanol. The solution was then treated slowly at 10C. with a solution of 4.7 ml. (0.14 mol) of hydrazine dissolved in 10 ml. of ethanol. The mixture was allowed to warm to room temperature and stand overnight. After heating for 1.5 hours at 40C., the product was concentrated at 1 mm. Hg to 60C. to yield 37.5 grams of diisopropyl phosphorodithioacetyl hydrazide having an index of refraction N 1.5220; and an average analysis of 9.6% N as compared to 9.8% N, theoretical.

EXAMPLE 3 Cal-I50 i 0 CH2 PSCHAZ INHN CRHs CH In a reaction flask containing 250 ml. of methyl ethyl ketone was added 0.1 mole of N,N-dimethyl chloroacetylhydrazide hydrochloride and potassium ethyl-ethoxy-dithiophosphonate along with 0.1 mole of potassium carbonate and 0.5 g. copper powder. The mixture was heated for 1 hour at reflux temperature. After this heating period the solvent was removed in vacuo. The residue was taken up in methylene chloride, washed with portions of water and dried over anhydrous magnesium sulfate. After filtering to remove the drying agent, the solution was filtered and the solvent evaporated. There was obtained 17 g. of a liquid identified as the title compound having an index of refraction n 1.5406.

The following compounds were prepared by a procedure substantially in accordance with examples 1 and 2.

EXAMPLE 4 1-C3H70 S CH:

\ II II l-S CH2C-NIIN i-GaILO CH Diisopropyl phosphorodithioacetyl dimethyl hydrazide having an index of refraction N =1 .4860; and an average analysis of 8.9% N as compared to 8.9% theorical.

EXAMPLE V 0,1150 s 0 CH:

9 SGH2 NHN 0211.0 N on,

Diethyl phosphorodithioacetyl dimethylhydrazide having an average analysis of 8.2% N as compared to 9.8% N, theoretical.

The following compounds may be prepared by a procedure substantially in accordance with examples 1 and 2.

EXAMPLE 6 CHaO\S F) i -S CHzCNHNHCH Dimethyl phosphorodithioacetyl formyl hydrazide.

EXAMPLE 7 CHsO Dimethyl phosphorodithioacetyl methylenehydraz'ide.

Although the new phosphoroacetylhydrazides have been found to be generally active as pesticides, their miticidal activity, especially with the two-spotted mite, Tetranychus lelarius, is unexpectedly high. Insecticidal activity for the phosphoroacetylhydrazides is illustrated in table I wherein the percentage kill among the pest species is reported for a Insect Test Species Musca domestica (Linn.) Blulella germanica (Linn.)

Oncopelms fascialus (Dallas) Housefly Gennan Cockroach Spotted milkweed bug Mite Test Species Two-spotted mite Tetrahychus telarius (Linn.)

In the screening tests for the insect species of table I, from 10 to 25 insects were caged in cardboard mailing tubes 3% in. in diameter and 2% in. tall. The cages were supplied with cellophane bottoms and screen tops. Food and water were supplied to each cage. Dispersions of the test compounds were prepared by dissolving one-half gram of the toxic material in 10 ml. of acetone. This solution was then diluted with water containing 0.0175 percent v/v Sponto 221, an emulsifying agent, the amount of water being sufficient to dilute the active ingredients to a concentration of 0.1 percent or below. The test insects were then sprayed with this dispersion. After 24 and 72 hours, counts were made to determine living and dead insects.

Some of the compounds which showed high mortality on house flies in the screening test were bioassayed on M. domestica. In this test, a known quantity of the toxicant was placed in a confined area. The same cages were employed as for the fly screening test. A weighed amount of the toxicant was placed in pyrex petri dishes having a surface area of 18.8 sq. centimeters along with 1 ml. of acetone. After the solvent was evaporated by air-drying, a cage containing groups of 25 female flies, 3 to 5 days old, was placed over the residue. Counts of living and dead insects were made 48 hours after initiation of the test.

TABLE I.MORTALITY OF REPRESENTATIVE SPECIES OF COMMON INSECT ORDERS AND MITES Of particular utility as pesticidal agents for controlling insects and acarids are the compounds dimethyl phosphorodithioacetyl formylhydrazide and dimethyl phosphorodithioacetyl methylenehydrazide. The phosphonate acetylhydrazides of the instant invention, are useful as pesticides for the control of insects and acarids. In particular the compound ethyl ethoxy phosphonodithioacetyl dimethyl hydrazide is useful as a pesticide to control insects and acarids.

It has been further found that the compounds of the present invention are excellent systemic miticides. In testing for systemic action, pinto bean plants were placed in bottles containing 200 ml. of the test solution and were held in place with cotton plugs. Only the roots were immersed. The solutions were prepared by dissolving the candidate miticide in acetone or other suitable solvent and then diluting with tap water. The final acetone concentration of the solution was never allowed to exceed 1 percent and the toxicant was initially tested at a concentration of 100 ppm. As soon as the plants were placed in the solution, they were infested with mites. Mortalities of post embryonic and ovicidal forms were determined 7 days after initiation of the test.

Although the above tests were accomplished with aqueous dispersions, the toxic compounds can also be used commercially in the form of aqueous solutions when appreciably soluble, non-aqueous solutions, wettable powders, vapors, and dusts as best suited to the conditions of use. ln many applications, fillers will be incorporated with the toxic compounds' For more specialized applications, the material may even be used in its pure, undiluted form.

When used herein the term pest" is intended in the restricted sense generally recognized in the art as applying to the lower forms of life customarily controlled by chemical means and excluding the higher animals, the vertebrates, for example, rodents, birds, and larger forms which are more .commonly controlled by mechanical means such as traps. It

will be apparent to one skilled in the art that the toxic activity demonstrated hereinbefore on various test species is indicative of activity with species and orders not specifically shown.

The foregoing description is given for clearness of understanding only and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

We claim:

1. The method of controlling pests selected from the group consisting of insects and acarids which comprises contacting said pests with a pesticidal amount of a compound having the formula wherein R is lower alkyl; R is selected from the group consisting of lower alkyl and lower alkoxy; the groups represented by X and X are independently selected from the group consisting of oxygen and sulfur; R and R are independently selected from the group consisting of hydrogen, methyl, ethyl, formyl, acetyl, and in combination can be selected from the group consisting of ethylidene and methylene.

2. The method according to claim 1 wherein said R is ethyl, R' is ethoxy, X is sulfur, X is oxygen, R is methyl and R is methyl.

3. The method according to claim 1 wherein said R is ethyl, R is ethoxy, X is sulfur, X is oxygen, R is hydrogen and R is hydrogen.

4. The method according to claim 1 wherein said R is methyl, R is methoxy, X is sulfur, X is oxygen, R is hydrogen and R is formyl.

5. The method according to claim 1 wherein said R is methyl, R is methoxy, X is sulfur, X is oxygen, R and R in combination are methylene. 

2. The method according to claim 1 wherein said R is ethyl, R'' is ethoxy, X is sulfur, X'' is oxygen, R2 is methyl and R3 is methyl.
 3. The method according to claim 1 wherein said R is ethyl, R'' is ethoxy, X is sulfur, X'' is oxygen, R2 is hydrogen and R3 is hydrogen.
 4. The method according to claim 1 wherein said R is methyl, R'' is methoxy, X is sulfur, X'' is oxygen, R2 is hydrogen and R3 is formyl.
 5. The method according to claim 1 wherein said R is methyl, R'' is methoxy, X is sulfur, X'' is oxygen, R2 and R3 in combination are methylene. 